The present invention is directed at the management of transactions in database management systems so as to enable greater concurrency, and therefore more efficient transaction execution, than is allowed by DBMS's requiring strict adherence to the traditional "ACID" properties of transactions. More specifically, the present invention is directed at solving the "serializability" problems introduced by long lived transactions (LLT's). In addition to DBMS's and transaction processing monitors, the present invention may also be used in persistent programming languages as well as to concurrency control services for object resource brokerage systems. For simplicity, the present invention will be described with respect to DBMS's.
The idea of revising or redefining the ACID properties of transactions to enable more efficient execution of transactions in systems that support LLT's is not new. However, the present invention provides a new methodology of "parameterized lock management" that is relatively simple to implement and that allows applications to explicitly control the degree to which they can tolerate diminished isolation between concurrent transactions.